/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.rop.code;

import com.android.dx.rop.type.Type;
import com.android.dx.rop.type.TypeList;

/**
 * Instruction which possibly throws. The {@code successors} list in the basic block an instance of this class is inside corresponds in-order to the list of exceptions handled by this instruction, with the no-exception case appended as the final target.
 */
public final class ThrowingInsn extends Insn {
	/** {@code non-null;} list of exceptions caught */
	private final TypeList catches;

	/**
	 * Gets the string form of a register spec list to be used as a catches list.
	 *
	 * @param catches
	 *            {@code non-null;} the catches list
	 * @return {@code non-null;} the string form
	 */
	public static String toCatchString(TypeList catches) {
		StringBuffer sb = new StringBuffer(100);

		sb.append("catch");

		int sz = catches.size();
		for (int i = 0; i < sz; i++) {
			sb.append(" ");
			sb.append(catches.getType(i).toHuman());
		}

		return sb.toString();
	}

	/**
	 * Constructs an instance.
	 *
	 * @param opcode
	 *            {@code non-null;} the opcode
	 * @param position
	 *            {@code non-null;} source position
	 * @param sources
	 *            {@code non-null;} specs for all the sources
	 * @param catches
	 *            {@code non-null;} list of exceptions caught
	 */
	public ThrowingInsn(Rop opcode, SourcePosition position, RegisterSpecList sources, TypeList catches) {
		super(opcode, position, null, sources);

		if (opcode.getBranchingness() != Rop.BRANCH_THROW) {
			throw new IllegalArgumentException("bogus branchingness");
		}

		if (catches == null) {
			throw new NullPointerException("catches == null");
		}

		this.catches = catches;
	}

	/** {@inheritDoc} */
	@Override
	public String getInlineString() {
		return toCatchString(catches);
	}

	/** {@inheritDoc} */
	@Override
	public TypeList getCatches() {
		return catches;
	}

	/** {@inheritDoc} */
	@Override
	public void accept(Visitor visitor) {
		visitor.visitThrowingInsn(this);
	}

	/** {@inheritDoc} */
	@Override
	public Insn withAddedCatch(Type type) {
		return new ThrowingInsn(getOpcode(), getPosition(), getSources(), catches.withAddedType(type));
	}

	/** {@inheritDoc} */
	@Override
	public Insn withRegisterOffset(int delta) {
		return new ThrowingInsn(getOpcode(), getPosition(), getSources().withOffset(delta), catches);
	}

	/** {@inheritDoc} */
	@Override
	public Insn withNewRegisters(RegisterSpec result, RegisterSpecList sources) {

		return new ThrowingInsn(getOpcode(), getPosition(), sources, catches);
	}
}
